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When to Plant Borage in Hardin County, OH

Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.

Hardin County, Ohio is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 20, giving you a growing season of approximately 177 days.

At an elevation of 935 feet, Hardin County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Borage during the growing season.

Hardin County, OH (Zone 5b) Moderate season
177 days
Last Spring Frost April 26
177 growing days
First Fall Frost October 20

Hardin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (83 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🍅 Harvest: Jun 6 – Jul 25
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Mar 22 Transplant: Apr 19 🍅 Harvest: Jun 14 – Aug 2
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Apr 7 Transplant: May 5 🍅 Harvest: Jun 30 – Aug 18

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Borage needs ~756 GDD — county provides 2,433 GDD Excellent fit

Borage Planting Timeline โ€” Hardin County, OH

Borage Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 โ€“ Apr 5
Transplant Outdoors April 19 Apr 19 โ€“ May 3
Direct Sow April 12 Apr 12 โ€“ May 3
Fall Sowing August 11 Aug 11 โ€“ Aug 25
Harvest June 14 Jun 14 โ€“ Aug 2

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Fall Sowing Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

50โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

177 days

Growing Tips for Hardin County

Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Borage in Hardin County, OH?

Hardin County is in Zone 5b with an average last frost of April 26. Plan your Borage planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hardin County, OH?

Hardin County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 20.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hardin County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hardin County, OH. Local conditions may vary. Last updated: April 2026.